Raetia, also spelled Rhaetia, ancient Roman provincecomprisingVorarlberg and Tirol states in present-day Austria, the eastern cantons of Switzerland, and parts of Bavaria and Baden-Württemberg states in Germany. Its native inhabitants were probably of mixed Illyrian and Celtic stock. The area was conquered by Rome in 15 bc and became an important part of the empire, but not for its economic value, which was small; rather, Raetia blocked the most convenient routes for an invader of Italy from the north by its control of a network of highways between Italy and the Danube River and between Gaul and the Balkan Mountains.

Because Raetia was a frontier province, its boundaries shifted in response to pressures from the German tribes. The northern line was moved north of the Danube to the Neckar River in the 1st century ad, but in the 3rd century intrusions by German tribes forced the western and northern boundaries to be pulled back. By 450 Rome controlled only the Alpine regions of Raetia.

Learn More in these related articles:

...Tiberius and his brother Drusus between 16 and 8 bc to conquer all the way to the great rivers of central Europe. New provinces were created in the Alps and Tyrol (Maritime and Pennine Alps, Raetia, Noricum) and also farther east (Pannonia, Moesia). Stability along the Danube was precariously maintained, under Augustus and later, by means of periodical alliances with Maroboduus and his...

The valleys were originally settled by the Raeti (Rhaeti), a people probably Celtic in origin. Most of the modern canton formed the southern part of Raetia, a province set up by the Romans in 15 bce. Designated a county by the emperor Charlemagne about 806 ce, the region was largely ruled from the episcopal see of Chur (Coire), the bishop of which had become a prince of the Holy Roman...

...on the Plessur River in the Rhine Valley. The meeting point of roads from Italy over several Alpine passes, it was important in Roman times as Curia Raetorum, the centre of the Roman province of Raetia. First mentioned in 452 as the seat of a bishopric, it was ruled in the Middle Ages by its bishops, who became princes of the Holy Roman Empire in 1170. Chur was the centre of the...